U.S. Pat. No. 3,161,676 describes a process for the preparation of a substituted urea by reacting a carbamic acid ester with a primary and sterically unhindered secondary aliphatic amines in the presence of a metal compound Lewis acid catalyst, such as cupric acetate.
There is no known prior art which describes the preparation of N-alkyl-monosubstituted carbamic acid esters by reacting an unsubstituted carbamic acid ester and an aliphatic primary amine in the presence of a monohydric aliphatic alcohol with or without the use of a tertiary amine catalyst.
Many important commercial applications have been developed for the carbamic acid ester products of this invention, for example, as herbicides, insecticides, medicinals and as chemical intermediates.